The present invention has for its object to provide a tuning alignment data memory device for tuning circuits tunable to selectable frequencies in which digital tuning alignment data corresponding to said frequencies are stored in a programmable memory (PROM) associated with said circuits, being selectable by a logic frequency selection circuit and suitable for having the associated digital tuning alignment data correspond to the selectable frequencies.
Such a tuning alignment data memory device is disclosed in the article by Daniel Dumont and Arno Neelen, entitled "Computer Controlled Television Channel Selection and Tuner Alignment", published in IEEE International Conference on Consumer Electronics June 5, 1985 pages 78-79.
Said article describes that the tuner of a television receiver is aligned in the factory by means of a computer. The digital tuning alignment data stored in the programmable memory correspond for each selectable frequency to supply voltage correction values for three varicap diodes which form part of three tuning circuits and which are coarsely tuned in a manner identical to that of a local oscillator. For each television channel a set of three digital tuning alignment data each corresponding to a supply voltage correction value for a varicap diode are therefore stored in the memory. Thus, considerable time is saved compared with the conventional manual aligning technique, consisting in adjusting each individual self-inductance of the tuned circuits, but there is a disadvantage.
Because, when for at least one of the selectable frequencies the writing in the programmable memory is faulty, be it only for one of the varicap diode correction voltage values of only one of the selectable frequencies, then the tuner is not suitable for use, which results in it being rejected when tested during a factory inspection.